Electric power generation that utilizes renewable energy, such as wind power generation and solar power generation, depends on weather conditions and thus does not produce stable outputs in some cases. Thus, outputs need to be leveled out by using an energy storage system, such as a Compressed Air Energy Storage (CAES) power generation system.
Conventional compressed air energy storage power generation devices are generally designed to store electrical energy in a pressure accumulator tank in the form of compressed air during off-peak periods for power plants and to drive an expander by utilizing the compressed air during higher power demand periods to operate a power generator, thereby generating electrical energy.
JP 2013-509530 A discloses such a CAES power generation device. The CAES power generation device disclosed in Patent Document 1 has heat medium tank separated from other components in order to decrease the temperature of a heat medium.